共 50 条
Hall conductance of a non-Hermitian two-band system with k-dependent decay rates
被引:2
|作者:
Wang, Junjie
[1
,2
]
Li, Fude
[1
,2
]
Yi, Xuexi
[1
,2
,3
,4
]
机构:
[1] Northeast Normal Univ, Ctr Quantum Sci, Changchun 130024, Peoples R China
[2] Northeast Normal Univ, Sch Phys, Changchun 130024, Peoples R China
[3] Northeast Normal Univ, Ctr Adv Optoelect Funct Mat Res, Changchun 130024, Peoples R China
[4] Northeast Normal Univ, Key Lab UV Emitting Mat & Technol, Minist Educ, Changchun 130024, Peoples R China
基金:
中国国家自然科学基金;
关键词:
Hall conductance;
non-Hermitian;
topological insulators;
BOUND-STATES;
D O I:
10.1088/1674-1056/ac9046
中图分类号:
O4 [物理学];
学科分类号:
0702 ;
摘要:
Two-band model works well for Hall effect in topological insulators. It turns out to be non-Hermitian when the system is subjected to environments, and its topology characterized by Chern numbers has received extensive studies in the past decades. However, how a non-Hermitian system responses to an electric field and what is the connection of the response to the Chern number defined via the non-Hermitian Hamiltonian remains barely explored. In this paper, focusing on a k-dependent decay rate, we address this issue by studying the response of such a non-Hermitian Chern insulator to an external electric field. To this aim, we first derive an effective non-Hermitian Hamiltonian to describe the system and give a specific form of k-dependent decay rate. Then we calculate the response of the non-Hermitian system to a constant electric field. We observe that the environment leads the Hall conductance to be a weighted integration of curvature of the ground band and hence the conductance is no longer quantized in general. And the environment induces a delay in the response of the system to the electric field. A discussion on the validity of the non-Hermitian model compared with the master equation description is also presented.
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页数:9
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